Early Stages of Evolution of the Black Sea

Abstract

AbstractComparison of two sets of structural and thickness maps of the Black Sea Basin produced by Russian and Italian workers revealed important differences in the interpretation of thickness and structure of the lower sedimentary unit, referred to in both works as ‘Palaeocene-Eocene’. The map based on the Italian data shows two depocentres with τ 5 km of sediment in the westernmost part of the Western Black Sea Basin (WBSB), while in the rest of the WBSB and in the Eastern Black Sea Basin (EBSB) the thickness is 2–3 km. Analysis of the land and submarine geology suggests that depocentres correspond to two segments of this system is represented by the Karkinit Graben on the northern shelf of the Black Sea. Submarine studies reveal that the graben originated behind and Early Cretaceous volcanic arc situated on the present day continental slope and rise.Most of the WBSB and the EBSB opened in the Eocene. For the EBSB this age is supported by data on its landward extension — the Adjaro—Trialet Basin. The EBSB could not open due to anticlockwise rotation of the Shatsky Rise because there was no corresponding subduction or shortening in the Greater Caucasus Basin. An alternative hypothesis is that of simultaneous opening of the EBSB and the WBSB as a result of southward drift of the Pontides and clockwise rotation of the Andrusov Rise.